Tension device for sewing machines



(N0 ModeL) L J. W. POST. TENSION DEVICE FOR SEWING MAGHINES.

' No. 317,193. Patented May 5,1885- UNITED STATES PATENT OFFICE.

JOHN W. POST, OF NEW YORK, N. Y.

TENSION DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 317,193, dated May 5, 1885.

Application filed January 22, 1885. (No model.)

To all whom it may concern:

Be it known that I, JOHN W. Posr, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Tension Devices for Sewing- Machines, of which the following is a specifification, reference being had therein to the accompanying drawings.

The object of my invention is to provide simple, effective, and cheaply-constructed tension devices for sewing-machines-such maohines,for example, as are shown and described in my application No. 100,868, filed July 14, 1883, of which this application is a division.

In the drawings, Figure l is a perspective view showing my main tension device and the contiguous parts of a sewing-machine. Fig. 2 is a section of the head of a machineand the said tension device. Fig. 3is a front view of the head of a machine, showing the supplementary tension device.

B indicates a portion of the bracket-arm of the machine, and O the head sustained thereby.

G is the needle-bar, and H the presser-bar, said bars having vertical bearings in said head, as is common in this class of machines.

The main tension device consists of a spring, K, secured to the top of the bracket-arm B by a single screw, K by which the stress of said spring may be adjusted. The rear end of the tension-spring is bent at a right angle to the main portion thereof, and the lower end of the vertical or bent part is formed with a concave seat fitting the round or convex upper surface of the bracket-arm. The forward end of the spring K bears on the top of the head 0, the needlethread being passed between said spring and the upper surface of said head.

A supplementary or check-tension spring, L, is secured to the front of the head 0 by a single screw, Z by which the stress of said spring may be adjusted, the free end of said spring L being steadied between two pins, Z Z. These steadying-pins Z Z are preferably arranged in different vertical planes, as shown, so that they will serve as guides for the thread which will be passed between them and beneath the spring L.

I claim- 1. The combination, with the bracket-arm B and head 0, of the tension-spring K, bearing on the top of said head and having a bent portion provided with a concave seat or-socket fitting said arm, and the securing and adjusting screw K passing through said spring into said arm, substantially as set forth.

2. The combination, with the head C, of the check-tension spring L, secured to the front face thereof, the screw P, for holding and adj usting said spring, and the pins Z Z, arranged 011 opposite sides of the free end of said spring for steadying the same, substantially as set forth.

3. The combination, with the head 0, of the checktension spring L, the screw 2*, for bold ing and adjusting said spring, and the pins Z Z, arranged on opposite sides of the free end of said spring and in different vertical planes, whereby said pins are adapted to steady said spring, and to serve as thread-guides, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN W. POST.

Witnesses:

E. D. SMITH, H. N. Low. 

